The technology disclosed relates to handling varying pixel overlaps along a first axis as a scanning head sweeps a curved path that is not parallel to the first axis. In particular, we teach use of a variable frequency pixel clock to produce equally spaced pixels along the first axis as a rotor arm scans a curved path that is not parallel to the first axis. The pixel clock has a varying frequency that varies approximately sinusoidally with the position of the scanning head relative to the first axis.
This design team recently has described in patent applications of rotor arm scanning system with very high throughput. The rotor arm scanner can, for instance, be used to write directly to large area masks.
The use of the rotor arm for scanning, instead of a shuttlecock with a reciprocating motion or a fixed head and a moving bed, is a radical departure from standard lithographic and imaging equipment. Use of the rotor presents very challenging data path issues, as the data is presented in a Cartesian grid that requires translation or mapping for use in a polar scanning system, in which the actual scanning path also involves linear motion of the workpiece as the scanning arm rotates.
Accordingly, many new components of a data path need to be developed. Many new problems not presented by prior lithographic technologies need to be identified and solved. Resolution of the many constituent engineering challenges has the potential of contributing to an overall system that has many times the pixel and area coverage throughput of prior, reciprocating systems.